


Rabbit Hole

by LadyGlinda



Category: Sherlock (TV)
Genre: First Time Blow Jobs, M/M, Masturbation, Mycroft Being a Good Brother, Sherlock Is 16 And Mycroft Is 23, Sibling Incest, Smut, Teenlock, holmescest
Language: English
Status: Completed
Published: 2019-10-27
Updated: 2019-10-27
Packaged: 2021-01-04 08:41:08
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,233
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21194807
Author URL: https://archiveofourown.org/users/LadyGlinda/pseuds/LadyGlinda
Summary: When their parents have to leave the country for a week, Mycroft comes home to keep his sixteen-year-old brother Sherlock company. The boy seems to be troubled by something, and Mycroft tries to help. And then he finds himself in the rabbit hole.





	Rabbit Hole

**Author's Note:**

  * For [SlytherinsDragon](https://archiveofourown.org/users/SlytherinsDragon/gifts).

“Sherlock… Are you all right?”

“Splendid.” Sherlock, sitting in an armchair in their parents' living room, hadn’t even looked up, pretending to be reading in a science book. He was dressed in rather tight jeans and a light-blue shirt.

Mycroft had not seen his brother for more than a year and he could hardly say he still knew him as well as he once had, as sad as it was. But even he could see that Sherlock was most definitely not feeling ‘splendid’, not even ‘all right’.

For a moment he just looked at his little brother, who was far from being little now. How much fourteen months could change someone his age. With fifteen, he had been lanky and a little clumsy, all long limbs and not-quite-right proportions. With sixteen, he was a man. Tall and thin but already starting to bulk up. He certainly shaved off his stubble every other day now. His face had become edgier, his prominent cheekbones dominating the frame. His lips were full and pink, his eyelashes thick and long. There was something amazingly different about his looks; they were androgynous and unique, sharp and appealing. He had turned into a beautiful young man in these past months…

Mycroft forced himself to stop thinking those foolish thoughts. This was not about his baby brother’s looks after all. Sherlock was suffering. And it was his job to find out why and what he could do about it.

Their parents had asked him to come home for a week. They needed to attend an appointment outside of England and they didn’t want to leave their younger son to himself, no matter how much older than his years his brain might be. Mycroft had arrived late at night and quietly entered the house to sleep in his old room, which was a guest room now, and he had only seen them for a moment in the morning before they had taken a cab to the train station.

Mycroft had agreed rather reluctantly to come to his parents' house. He had not taken a single day off since he had started working for the government. Somehow it felt wrong to leave and not… well, not be in control. It was silly of course. He could do some work from home with his laptop; he was reachable via mobile phone and the world would not end because he couldn’t go to the office for a week, and neither would his career. And he had neglected Sherlock so much over the past years, ever since he’d gone to university. His smart little brother had almost become a stranger to him. And the bright boy with the wide smile had first become a grumpy teenager and now a melancholic young man who refused to tell him what was bothering him. He couldn’t let him get away with it so easily and he simply owed it to Sherlock to be persistent. It was time and the perfect opportunity to restore their brotherly bond.

“Is it because of school?” he asked, and Sherlock looked up, a flicker of pain in his eyes.

“No,” he answered, and it was clearly a lie.

“It can’t be easy,” Mycroft said. “It wasn’t for me.”

Sherlock snorted. “Pardon? You were the perfect pupil, then the perfect student and now you’re running the country.”

“Well, that’s not nearly the truth,” Mycroft said, shaking his head. His brother might have forgotten how chubby Mycroft had become when he had been twelve. He had been mocked and nobody had liked him in the first place; he had been too smart and too aloof. Sure, he had thought they were far beneath him on an intellectual level but a lot of his cold behaviour had rooted in insecurity as he had lacked social skills and he had known it. He had been unable to connect with anyone and so he hadn’t had any friends. And nothing had changed about that… Nobody was mocking him anymore, at least not openly. He moved around the rich and the influential with grace and diplomacy now, scheming his way to reach his goals to the benefit of the country. But people still didn’t like him. Not that he cared. The older he had become, the less had he liked humanity in general. Goldfish. Idiots. Not worth wasting any energy at them. But this was _Sherlock_. No goldfish. Definitely no idiot. And the only one who mattered to him beside their parents. “Things are not always what they seem,” he settled for.

“Yes, right. You don’t have to sit around with me. I’m sure you have more interesting things to do.” But Sherlock didn’t sound as if he wanted him to leave.

And Mycroft didn’t plan to. “You can tell me. Whatever it is, I’m sure we can find a solution.”

“Ah, no. There is no solution for it.”

At least he was admitting now that there was indeed a problem. And Mycroft may be still young himself, but he was already sure that he would find a solution for whatever problem his brother was dealing with. “Try me.”

Sherlock gave him a pained look. Then he shook his head. “It’s… too embarrassing,” he mumbled darkly.

“I’m your brother, Sherlock. You can tell me anything. I won’t laugh and I will just try to help if I can.”

“But you can’t! It’s… It happened after gym class. I… Oh, I can’t tell you.” Sherlock put his book aside and got up, proceeding to flee the room.

Mycroft tried to step in his way but his brother hurried around him gracefully, and Mycroft could see him hastening up the stairs. A moment later a door was shut at the end of the upper floor. So he had retreated into his bedroom like Mycroft had expected.

The young politician argued with himself whether he should follow Sherlock or leave him for now. But he knew if he didn’t go to him now, Sherlock would close up even more. So he decided to confront him again. He had some experience with dealing with rather complicated personalities after all. His little brother, as intelligent as he was, was no match for him.

Sherlock didn’t answer when he knocked at the door, but it was not locked when he tried to enter.

He poked his head in. “May I come in?”

“If you must...” Sherlock was lying on his bed, a pillow stuffed behind his head. Now he had no book in his hand; he wasn’t even pretending to be busy anymore.

The room was surprisingly neat for a teenage boy. Well, Mycroft's had been, too, but he had not been a typical teenager. Oh well, neither was Sherlock of course. But Mycroft had not known he liked his surroundings so tidy these days. He could remember other times. Child Sherlock's room had been a mess to put it nicely. But that didn’t matter now.

He looked pointedly at the empty chair next to Sherlock's bed, and his brother nodded, his expression unreadable.

“You don’t have to tell me anything if you don’t want,” Mycroft began. “But sometimes it does help to talk about it and...”

“It was about my cock,” Sherlock blurted, and Mycroft all but gaped at him.

He had not expected anything that… touchy… But he shook off his irritation at once. “Your...”

“...cock, yes, I said. They saw it when we showered. I usually don’t shower with them because they are stupid and I only want to get away as soon as I can but I had to see the dentist directly after school and there was no time to go home in between.” Sherlock stopped after this flood of information, having run out of breath.

Mycroft gave him an encouraging nod even though he would have preferred not talking about his brother’s… penis. But he had started this conversation and he would endure it now. And they were brothers. They could talk about such things. No big deal! Oh, well…

“So… They looked at me and laughed.” Sherlock was worrying his bottom lip with his teeth now.

“Um… Okay… And…”

“They said it looked funny.”

Mycroft had a sudden vision of Sherlock, completely naked. His pale, smooth skin all exposed, the soft curve of his beautiful… _bum_… His… _cock_… Oh God… Somehow it had become difficult to breathe. “Funny?” he croaked, hardly aware that he had even opened his mouth.

“Yes, I’ll show you.”

_No!_ Mycroft wanted to scream but no sound escaped his mouth.

Sherlock opened his zip with his _[imposs__ibly beautiful, long, elegant] _fingers and a moment later the object in question sprung free from its confinements.

Mycroft had seen a cock or two in his university years. Having figured out he was gay when he had still been this chubby, unattractive and insanely introverted boy, he had not been around the block but made some experiences as soon as he'd been away from home. They had not been very interesting. Physically pleasant to some extent, yes, but since he hadn't cared for any of these men, who had tried so hard to appeal to him, having sex had felt shallow and dull at best, and icky and depressing at other times so he had quickly ceased from doing anything.

But now that he was looking at his _little brother's_ exposed cock, he didn’t feel exactly bored, let alone appalled. Sherlock's cock was long and thick, with a very wide crown – and it was half-hard. It didn’t look funny in the least. It looked gorgeous and arousing and edible…

Mycroft was feeling positively dizzy now. And his own cock, which looked tremendously similar to Sherlock's, was throbbing in his pants. He should immediately withdraw from this situation. It was the only reasonable thing to do.

“You think it looks funny, too,” Sherlock said, darkly.

“What? No. It's beautiful…” Oh Lord… What the hell was he saying here?!

“Ah, I don't believe you,” Sherlock muttered. “Yours is much bigger and looks totally normal I bet.”

Mycroft, sitting frozen in his chair, shook his head. “No, it looks very much the same. There is no 'normal' when it comes to… penises. They all look unique. There is nothing wrong with yours. And it's actually… very… big…” Would he start drooling now? Could this get any more embarrassing?

Sherlock shook his head, stubbornly. “I don't think so. Mine is ugly and no man will ever want to touch it.”

Had he known that Sherlock was gay, too? Probably yes. At least it was no surprise whatsoever. Not that many developments could have surprised him anymore in this moment… “I'm telling you, it's…”

“Show me, then.”

“What?” He must have fallen down the rabbit hole. Or perhaps this was a dream? No. He was too rational to believe in any of these explanations. This was real and he had brought himself into this situation, insisting that Sherlock should talk to him, assuring him that whatever problem he had, they could talk about it. But this wasn't talking anymore… “No, Sherlock. That would not be appropriate.”

Sherlock snorted but it almost sounded like a sob. “I knew it. You think mine is ugly, damn, you think _I'm_ ugly and you're right.”

“No! You're as far from being ugly as you can get! You're beautiful and special and perfect and so is your penis.”

Sherlock looked up to him and was there a tear in his right eye? He couldn't watch his brother crying for God's sake!

The next moment he was fumbling with his flies and then he brought the matter to light. His large cock, blood-filled and heavy, snapped out of his trousers like a snake ready to attack.

“Oh,” made Sherlock, and he sat up and shuffled towards the edge of the bed. “It really looks like mine. But it's longer. And thicker.”

“Not by much. It's basically… DamnSherlockwhatareyoudoing?”

“It feels so silky,” Sherlock purred, his long fingers wrapped around Mycroft's now dripping cock, stroking up and down firmly, and God it felt so good…

“Let me go,” Mycroft whimpered even though his groin was screaming _'touch me even harder!'_ “We can't do this! You're…”

“…_my little brother, you're not even eighteen and it's incest and forbidden_…” Sherlock calmly finished his sentence for him, his hand relentlessly stroking up and down on him.

Gone was all insecurity and despair, his eyes looking up to Mycroft triumphantly through these marvellous lashes, and finally Mycroft understood. There had been no awkward showering with his classmates, and even if he had done that, nobody had mocked him and why should they – Sherlock's cock was a perfect specimen. And damn, even if they had, Sherlock wouldn’t have given a damn for what they said and probably tore them to shreds with firing off deductions that were as accurate as they were nasty…

“You've planned this,” he rasped out, shivering under his brother's deft touches. He had probably not done this for anyone else before but he had definitely been practicing with himself and mastered it.

“You always said you're the smart one,” Sherlock chuckled.

When had he said this the last time? He must have been thirteen… And he had just proven that he, in fact, was an innocent _idiot_ compared to his cunning, determined little brother. Determined to get him off. Determined to get him…

“Sherlock, no, please,” he brought out. “You will regret this and if it comes out, I'll be in huge trouble.”

“Mycroft, I've been fantasising about doing this for three years, waiting until I'm of age so you wouldn’t totally freak out, and no, I'm not going to regret it. And do you really think I'd allow this to come out? We'll have this house for ourselves for a full week and I'm not planning to leave this bed besides going to the bathroom or eating something. We will do it again when you come home for Christmas and our parents go to church. And as soon as I'm eighteen, I'll go to a science school in London and live with you and we can have sex every night; nobody will think anything by it - two brothers sharing a flat in this expensive city.”

“But… Why… Why me?”

“Seriously? Who else? Do you think I want to waste my time with some stupid morons out there? And I have a high sex drive; I need it all the time and in between I'd like to have a conversation with the man and I'd prefer if he understood what I'm saying.”

This was a rabbit hole within a rabbit hole… But even in the parallel universe he had to be in, Sherlock's hand was still doing most arousing things to his cock, and now…

“Hell, no, Sherlock…” Whatever he had wanted to stammer ended in a moan when his brother's fantastic lips closed around his member. He started sucking him, and he was doing it damn well. Probably he had practiced this too, with some innocent vegetable in all probability.

He should push him away but instead he was only pushing into his little brother's mouth, and Sherlock didn’t seem to be put off by it but rather pleased, his eyes sparkling when he went cross-eyed to meet his dazed glance. Mycroft stared down on him, every ability to speak having left him for now, and he could feel his climax approaching in full speed.

And when he came, so abruptly and sudden that he couldn’t even warn his brother, Sherlock took his explosion with ease; he didn’t even gag, only his fluttering eyelids and some minor sniffling gave away that it was some effort to swallow all the sticky fluid. Sherlock had always liked to do experiments and without a doubt he had simulated his come shot with God knew what and was able to take it as if he had never done anything else.

Mycroft slumped in his chair like a balloon that had been suddenly emptied. And then he opened his eyes widely when Sherlock squeezed his softening cock, hard, and some more white fluid dribbled out of it, and Sherlock scooped it up with his hand and wrapped his soiled fingers around his own cock, pumping it mercilessly, and before Mycroft could even react, he was coming, too, shooting all over Mycroft's still clothed thighs and his now flaccid cock, and then he let himself fall backwards onto the bed.

For about ten seconds they were both silent beside their harsh breathing, and then Sherlock sat up again. “I'll need about ten minutes until I'm ready again. You?”

“Oh… I… I don't know.” He had never had a second round…

“Ah, I guess it's a tad longer, no problem. I can prepare us some sandwiches?” Sherlock offered.

“That… That would be nice.” This had really happened. His baby brother had given him the best blowjob of his life and then masturbated with the help of Mycroft's sperm and now he was counting the minutes until they would have more sex. This was just madness… It would be his downfall and…

He winced when Sherlock's face was suddenly very close to his own, the mercurial eyes narrowed.

“Forget it, Mycroft. Don't waste our time with feeling guilty and this shit. I wanted it, I'll still want it in five years and ten years and it's nobody's business but ours. Nobody will ever find out and your career is in no danger. We'll have so much fabulous sex, in every position and every possible way. I want to do it all with you, things you haven't even dreamt about before. Of course only you and me; even if it wasn't too dangerous I wouldn’t allow anyone else to touch you. You have to promise me that you won't do anything with another man until I can move in with you. I'd get very cross.”

Mycroft shook his head, dumbly. “No. Nobody else.”

Sherlock smiled. “Good. Oh… Before I go…” And then he kissed Mycroft, and that was something he had not been able to practice. It was messy and a bit toothy but when Mycroft kissed him back, leading the way for now, he very quickly adjusted to it, and when they parted minutes later, Sherlock knew everything about French kissing anyone needed to know. Mycroft's brain was spinning, and Sherlock's eyes were dazed as well.

“Bloody hell, that was nice,” Sherlock stated and straightened up. “Why don't you lie down on the bed until I'm back with the sandwiches? You need to recover and I'll make sure you get enough strength.” He chuckled happily and Mycroft just nodded, moving his body, which felt heavier than ever, over to the bed and collapsed onto it backwards. He was still wearing his soiled trousers but he was feeling unable to remove them. Sherlock would do that anyway. He would feed him and then be all over him, with the same determination with which he had planned their future life.

And Mycroft would follow him. He would follow his smart, cunning, manipulative, sexy and irresistible little brother wherever he wanted to go with him. It was pointless to argue with him and really – he didn’t want to.

It seemed it was _Sherlock & Mycroft_ now.

And frankly – this was fine with him because whom did he want to fool. He was madly in love with his highly remarkable baby brother.


End file.
